Sheet feeding machine



Dec. 29, 1959 R. L. SJOSTROM SHEET FEEDING MACHINE Filed July 26. 1956 2Sheets-Sheet l INVENTOR.

1959 R. L. SJOSTROM SHEET FEEDING MACHINE 2 Sheets-Sheet 2 Filed July26. 1956 ROM z JIDNVENTOR BY 7m United States Patent SHEET FEEDINGMACHINE Robert L. Sjostrom, Miami Beach, Fla.

Application July 26, 1956, Serial No. 600,191

8 Claims. (Cl. 271-33) The present invention relates to a device forsuccessive removal of individual sheets of material from a stack ofsheets and the successive delivery of the sheets to a desired location.

In the textile and laundry field, there has always been considerablediiiiculty in removing sheets, towels, pillowcases or other similarelements from a stack and delivering them individually to some desiredlocation, such as an ironer or folding machine. Attempts have been madeto satisfy this problem by removal of the sheets with the use of suctioncups and fingers. However, attempts of this nature have uniformly failedfor a number of reasons. Attempts have been made in the paper industryto feed sheets of material with the use of an adhesive material; whiledevices used for this purpose in the paper field may have beensatisfactory for that type of operation, the machines are not suitablefor delivery of textile materials for the means of stripping the sheetmaterial from the adhesive are not positive and consequently do notprovide a certainty of operation.

The present invention is directed towards a device of the type generallyindicated in which individual sheets are picked from the top of a stackby an adhesive material. The sheet material is subsequently removed fromthe grip of the adhesive material by a positive acting arm which isactuated at a selected position.

In the present invention, the adhesive material is provided in the formof a roll of adhesive tape with means providing a fresh surface of tapefor each new sheet of material being picked up. Used tape is rolled ontoa second spool.

The stripping of the sheet material from the adhesive surface and theprovision of a fresh surface area of adhesive material for a subsequentoperation are simultaneously provided from a common operating sourceactuated by a switch at a selected point.

There is also provided an automatically adjustable table to support thestack of sheet materials at a selected level for removal of theuppermost sheet from the stack.

These and other objects and advantages of the present invention will bemore clearly understood when considered in connection with theaccompanying drawings in which:

Figure 1 is a cross sectional somewhat schematic side view of theinvention.

Figure 2 is an enlarged detail of one of the pickup units illustrated inFigure 1, and

Figure 3 is a detail of the supporting arm mechanism.

In this arrangement, a suitable frame 1 having suitable side, end andbottom walls is provided with a centrally located well section 2. Atable section 3 is horizontally positioned in the well 2 and issupported at its end by arms 4 and 5. Each of these arms 4 and 5 areprovided with bearings 6 and 7 respectively. These bearings in turnthread onto the shafts 8 and 9 respectively and are adapted to move upand down on the shafts when these shafts are rotated. The shafts aresuitably mounted for rotation in bearings 10, and each is provided withbevel gears 11 at their lower end. A common operating shaft 12 providedwith bevel gears 13 at either end interengages the bevel gears 11 and isthereby operatively connected to them. The shaft 12 is connected to areversing motor 14 through a, suitable arrangement, such as theinterengaging gears 15. The motor 14 is thus able to raise and lower thetable 3 through rotation of the shaft 12 and consequent rotation of theshafts 8 and 9. The shafts 8 and 9 should be provided with opposingthreads in the particular modification of the invention shown in thedrawings.

The motor 14 should be provided with a suitable on-olf and up-downcontrol for proper movement and control of the table 3. A limitingswitch 16 should also be connected in series with the up control to thereversing motor 14. This limiting switch 16 is supported on the arm 17which is fixed at its other end 18 to the top of the frame 1. The switch16 may be a mercury switch adapted to close the circuit through themotor when the master switch is closed to permit an upward movement.This limiting switch 16 has a contacting wire 19 secured at one end tothe mercury elements of the mercury switch and the other end curveddownwardly and adapted to engage the upper surface 20 of the stack ofsheet material. The finger 19 will normally move downwardly closing theswitch 16. When this occurs, the motor 14 is energized and the table 3moves upwardly until the top of the sheet material 29 engages the curvesection of the finger 19 raising it and consequently opening the switch16 and turning the motor 14 off. In this manner, the sheet material2il'may be kept with its upper surface at a constant level suitable forthe pickup elements of the present invention.

A pair of lever arms 30 are mounted on a transverse shaft 31 at theforward end of the present invention. The shaft 31 is in turn suitablymounted in bearings 32. A motor 33, suitably secured to the frame,interengages a lever extension 34 which is secured rigidly at one end tothe shaft 31. This interengaging may be provided by a lever linkagesystem 35 comprising a lever arm 36 mounted on the motor shaft with apin and slot arrangement 37 as illustrated. Thus, the rotation of themotor 33 will cause a reciprocating action of the parallel arms 30 froma position above the stack of material 20 to a position beyond thepresent invention. A cross beam member 39 extends between the upper endsof the parallel arms 30 and is secured rigidly to them. On this crossbeam 39 there is mounted a pair of pick-up elements generally designated49. These pick-up elements 49 are secured against lateral movement alongthe beam or shaft 39 by suitable means, such as retaining rings atadjustably spaced positions. The pick-up unit 40 is provided with aT-shaped frame having outwardly extending arms 41 and 42 and adownwardly-extending arm 43. A pair of drums or rollers 45 and 46 aremounted on the shafts 43' for rotation with the shafts 43 in turnmounted on the arms 41 and 42 towards the outer ends thereof. At thelower end of the member 43 there is mounted for free rotation, a rolleror small drum 47, which may be rotatably secured to the member 43 by theshaft 48. A roll of adhesive tape 49 is mounted on the drum 46, and ithas its end threaded downwardly under the roll 47 and up onto the drum45.

The shaft 43' extends through the arm 41 and is rotatably mounted in it.This shaft 43' has a gear 50 secured at its end on the side opposite theside onwhich' the drum 45 is secured. Also secured on the opposite sideof the supporting frame is a solenoid 51 having a downwardly-extendingplunger arm section 52 and an upwardly extending plunger 53. At thelower end of the plunger arm section 52 there is secured a stripper arm54 which is provided with a flange section extending inwardly towardsthe roller 47 but terminating just short of it. At the'upper end of thesolenoid secured to the plunger section 53 there is secured a lever arm56 pivotally engaged n57 to the plunger 53 at one end and pivotallyengaged at the other end 58 to the pawl 59. The pawl59 is pivotallysecured to the arm 41 by a pin 60 and has a tooth-engaging section 61projecting beyond and adapted to successively engage the teeth 62 on thegear 50. The plunger 53 and 52 are maintained in a normal up position bythe spring 65 connected at one end to the lever 56 and at the other endto the supporting frame. A spring detent 70, secured at one end 71 tothe arm 41, is adapted to engage the teeth 62 and prevent slipping ofthe drum 45. The solenoid 51 is controlled electrically by a switch 80which may be located on the lever arm 30. The limit switch 80 is adaptedto be engaged by the trip element 81. The trip element 81 may beadjustably positioned on the bearing or support element 32 or in someother suitable manner so that the trip element 81 will engage the switch80 at any selected position of rotation of the arms 30. When the switch80 is engaged, the solenoid 51 is actuated. This moves the plunger armdownwardly causing the stripper to bear against sheet material which haspreviously been adhered to the strip of adhesive material extending overthe roller 47. The arm 54 is sufficiently close to the roller 47 andmoves sufiiciently beyond it to disengage the sheet material from theadhesive. Simultaneously, the pawl 59 moves the gear 50 one notch,turning the drum 45. and consequently unrolling the adhesive materialfrom the drum 46 onto the drum 45. The amount of adhesive material sounrolled is dependent upon the number of teeth on the gear 50,preferably a quarter of an inch of tape is unrolled in each cycle.Normally, the solenoid 51 is actuated when the arms 30 have positionedthe pick-up element 40 at a point such as 90. At this point the forwardedge of the uppermost sheet material, which has been picked from thestack 20, may be deposited onto a successively positioned machine, suchas a folding machine. The operation of the motor 33 then reverses themovement of the arms 30 whereby the pick-up elements 40 are returned tothe stack of material 20 for a successive operation. The pick-up unit 40may be provided with a limit switch 91 having a finger member 92 whichcontrols the limit switch and is adapted to bear against the tape at 93.This limit switch 91 is connected in series with the motor 33 so thatwhen the tape accidentally breaks, the limit switch 91 is opened,thereby causing the motor 33 to stop permitting an immediate replacementof the tape or other repair to it.

, If desired, the two pick-up units 40 positioned on the shaft 39 may beselectively positioned along the shaft 39 to adapt the machine for usewith stacks of material of diiferent widths.

The pick-up elements 40 must be maintained in a vertical position inorder to ensure the proper operation of the present invention. Toaccomplish this the pick-up element40 is keyed to the shaft 39 bysuitable means, such as a key element 101. The shaft 39 is freelyrotatable in the arms 30. At one end of this shaft 39, preferablypositioned beyond the arms 30, there is also keyed a sprocket 102 by asuitable keying element such as indicated at 103. V The sprocket 102 isinter-engaged with the sprocket 104 by the chain 105. The sprocket 104is fixed on a sleeve 106 which is in turn fixed to the frame or someother suitable member such as the bearing 32; thus, as the arms 30 arepivoted back and forth by the action of the shaft 31 to which these arms30 are keyed, the sprocket and chain arrangement will tend to keep thepick-up elements 40 in a normal vertical position.

Having now described my invention, I claim:

1. In a device for delivering individual sheets from astack of sheetelements, a pick-up element comprising rotatable drums, a length ofadhesive material wound at spaced positions on said drums, bearing meansover which said material extends intermediate said drums with saidadhesive material providing a contact area for engagement With a sheetelement, a stripping arm having a projecting portion positioned adjacentto said bearing means, a solenoid operatively engaging said strippingarm and adapted to project it from a position normally above to aposition below said bearing means, and means operatively interengagingsaid solenoid and adhesive material for advancing said adhesive materialover said bearing means.

2. In a device for delivering individual sheets from a stack of sheetelements, a pick-up element comprising a supporting frame member,rotatable drums mounted on said frame member, a length of adhesivematerial wound on said drums with an intermediate portion facingdownwardly, a bearing means for and positioned above said intermediateportion, a stripping arm having a projecting downwardly movable arm, asolenoid operatively engaging said arm and adapted when actuated to moveit from a position normally above to a position below said bearingmeans, and means including a pawl and ratchet operatively engaged withsaid solenoid for advancing said adhesive material over said bearingmeans.

3. A device for delivering individual sheets from a stack of sheetscomprising in combination a self-adjusting table for receiving a stackof sheets with means for maintaining the upper surface of the same at aconstant level, a pick-up unit having means supporting an elongatedstrip of adhesive material with said adhesive material for engaging asheet, means providing a bearing surface for a section of said material,means for vadvancing said mate--,

rial in intermittent increments over said bearing surface,v strippingmeans for removing said sheet from said adhesive material and means forsynchronously actuating said stripping means and said means foradvancing.

4. A device for delivering individual sheets from a stack of sheetscomprising in combination a plurality of pickup elements each comprisinga frame, rotatable drums mounted on said frame, a length of adhesivematerial Wound on said drums with an intermediate portion facingdownwardly, a bearing means for and positioned above said intermediateportion, a stripping element mounted on said frame and including an armpositioned for longitudinal movement between points just above and belowsaid bearing means, arm actuating means, a frame member mounting saidpickup elements in parallel, means for moving said frame over an arcuatesector to and from a point above said stack, and means for synchronouslyactuating said last mentioned means and said arm actuating means.

5. In a device for delivering individual sheets from a stack of sheets,a pick-up element comprising a length of adhesive material, meansmounting said material for engagement with an individual sheet, meanshaving a movable stripper arm, and solenoid means operatively engagingand said arm for moving saidarm beyond but adjacent to said materialwhereby said arm is adapted to contact and remove said individual sheetfrom said material.

6,. In a device for delivering individual sheets" from a stack ofsheets, a pick-up element comprising a length of adhesive material,means mounting said material for longitudinal movement, bearing meansover which said material extends with said material providing a contactarea for engagement with an .individual one of said sheets, meanshavinga projecting stripper arm, means for actuating said arm to apositionbeyond but adjacent said material in a plane normal to saidsheets at the point of contact of said material to strip it from theadhesive material, and means for synchronously actuating said means foractuating said arm and longitudinally advancing said adhesive material.g V

7, In a device for delivering an individual sheet from a stack ofsheets, a pick-up element comprising rotatable drums, a length ofadhesive material wound at spaced positions on said drum, bearing meansover which said material extends intermediate said drums with saidmaterial providing a contact area for engagement with said sheet, meanshaving a projecting stripper arm, means for actuating said arm to aposition beyond but adjacent said material in a plane normal to saidcontact area to strip said sheet from the adhesive material and meansfor simultaneously actuating said arm and advancing said material oversaid bearing means.

8. In a device for delivering individual sheets from a stack of sheets,a pick-up element comprising a frame, rotatable drums mounted forrotation on said frame, a length of adhesive material wound from onedrum to the other, bearing means under which said material extendsintermediate said drums with said material providing a contact area forengagement with a sheet, means mounted on said frame having a projectingstripper arm positioned adjacent to and just above said bearing means,actuating means operatively engaging said arm and adapted to projectsaid arm below said bearing means for disengaging said material andsheet, and means operatively interengaging said actuating means anddrums for intermittently advancing said adhesive material over saidbearing means in a synchronized movement with the operation of saidactuating means.

Dvorak Apr. 16, 1901 Rider June 13, 1944

